<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        li{
            float: left;
            list-style: none;
        }
        .box{
            width: 1000px;
            /* margin: 100px auto; */

        }
        .box li {
            float: left;
            
            width: 200px;
            height: 200px;
            background-color: pink;
            margin: 15px;
            /* background: url();   */
            /* ()里面的放精灵图的路径位置 */
        }
    </style>
</head>
<body>
    <div class="box">
       
        <ul>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>
    </div>
<script>
    var lis = document.querySelectorAll('li');
    for( var i = 0; i < lis.length; i++){
        var index = i * 44;
        lis[i].style.backgroundPosition =  '0 - '+index+'px';
    }
</script>
</body>
</html>